The Quadro plugin brings qualitative data analysis (QDA) capabilities to Obsidian, offering an open-source alternative to proprietary software like MAXQDA and Atlas.ti. It allows researchers to store and analyze qualitative data in Markdown format, making it accessible, future-proof, and compatible with other tools. Quadro supports coding (assigning tags to text) and extraction (transforming text into structured data), using bidirectional links between Data and Code files. This plugin also integrates seamlessly with Obsidian's features, such as Graph View and Outgoing Links, and can be extended using other plugins. With a focus on flexibility and customizability, Quadro provides an adaptable solution for qualitative research workflows.